campbell



(No Model.) 6 Sheets-Sheet 1. O. H. CAMPBELL.

PAPER PULP SCREEN. No. 407,996. Patented July-30, 1889.

WITNESSES I INVENTOR yflcw W 7 ATTORNEYS Martins Photo-Lithography. Wnhlnglnn, n c

(No Model.) 6 Sheets-Sheet 2.

O. H. GAMPBELL.

PAPER PULP SCREEN. No. 407.995. Patented July 30, 1889.

WITNESSES; p S INVENTDVR' 606m g wm (No Model.)

. 6 Sheets-Sheet 3. O. H. CAMPBELL.

PAPER PULP SCREEN.

- Patented July 30, 1889.

- INVENTOR ATTORNEYS ETERS. PhahyLiihngnphar Wishln o D (No Model.) I 6 Sheets-She'et 4.

05H. CAMPBELL. PAPER PULP SCREEN.

No. 407,995. Patented July 30, 1889.

Ex x4 WITNESSES M M A di 3232 BY mu M 24 W ATTORNEYS (No Model.) 6 Sheets-Sheet 5.

G. H. CAMPBELL. PAPER PULP SGREEN.

No. 407,995. Patented July 80, 1889.

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wnuasszs: INVENTOR 25 'iiwww w 74 Q ATTORNEYS (No Model.) 6 Shets-Sheet 6.

G. H. CAMPBELL.

PAPER PULP SCREEN. S No. 407,995. Patented July 30, 1889.

WITNESSES:

1 l INVENTOR UNITED STATES PATENT OEEIQE.

CHARLES H. CAMPBELL, OF lVATERTO\VN, NE\V YORK, ASSIGNOR TO THE BAGLEY & SEWALL COMPANY, OF SAME PLACE.

PAPER-PU LP SCREEN.

SPECIFICATION forming part of Letters Patent No. 407,995, dated July so, 1889.

Application filed April 12, 1889. Serial No. 306,923. (No model.) i

To all whont it ntay concern.-

Be it known that 1, CHARLES H. CAMPBELL, of \Vatertown, in the county of Jefferson, in the State of New York, have invented new and useful Improvements in Paper-Pulp Screens, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention consists in a novel organization of a paper-pulp screen in which the interstices of the screen are cleared and the pulp drawn through the same by means of alternate blasts and suctions of air to and from an air-space beneath the screen-plates, and thus the process of screening the pulp is expedited without producing the jarring of the apparatus and resultant noise and wear and tear thereof, which is one of the defects of the class of paper-pulp screens hitherto generally used.

The invention also consists in certain peculiarities of the details of construction of the paper-pulp screen and auxiliary devices connected therewith, as herein after fully described, and specifically set forth in the claims.

In the annexed drawings, Figure 1 is a rear elevation of a paper-pulp screen embodying my improvements. Fig. 2 shows the same on a reduced scale and in connection with one of the species of air-blowing and air'exhausting apparatus adapted for the purpose hereinbefore stated. Fig. 3 is a top plan view of my improved pulp-screen with portions of the screen plates broken away. Fig. 4: is a vertical transverse section on line a: 00, Fig. 3. Fig. 5 is a vertical longitudinal section on line y y, Fig. 3. Fig. 6 is a detached perspective view of the screen-frame. Fig. 7 is an enlarged vertical transverse section of the airblast and air-suction pipe and valve connected therewith, taken in a plane parallel with the axis of said valve. Fig. 8 is a vertical transverse section of the same in a plane at right angles to the axis of the valve, and Fig. 9 is a top plan view of the same.

Similar letters of reference indicate corresponding parts.

A represents the pulp-vat, which is formed with a bottom A, which is inclined from one side of the vat to the opposite side thereof, and at the lower side of said bottom the vat is formed with a pulp-trough B, through the bottom of which projects upward the overflow-pipe O, which conducts the screened pulp to the paper-making machine. A vertical plate c, extending lengthwise of the trough B between the pipe 0 and adjacent side of the bottom A and having its top edge above the plane of the said bottom and its lower edge in a plane below the mouth of the pipe 0, forms a water seal, which prevents air from passing from the space over the bottom A to the pipe 0. The mouth of this pipe is lower than the lower side of the bottom A, and consequently leaves an air-space under the screen.

The main portion or body of the vat A is extended part way over the trough B, as shown at A, and said extension is provided with a ledge or bottom B, which reaches part way toward the main bottom A and is nearly or quite on a level with the elevated side of the latter bottom. On theledge or bottom B and elevated side of the bottom A is seated the screen-frame B, leaving a gutter D along that side of the said frame which rests on the ledge B. The screen-frame has the screen-plates 13 secured to its top in the usual manner. The side of said frame which rests on the elevated side of the bottom A is formed with horizontal ports (1 (Z d, and along the said side of the screen-frame a trough E is formed in the vat A, which trough is closed at the top by a plate 6, resting with one edge on top of the screenframe and with the opposite edge on the top edge of the trough, and thus the latter is converted into an air-duct. Another trough F is formed in the vat A along the outer side of 0 the said air-duct, and in said trough is introduced the pulp to be screened. Any heavy foreign substance which may be in the pulp will settle in the trough F, and the pulp flows over the top of the plate 6 and onto the screen, as indicated by arrow in Fig. A of the drawings.

B represents an air-pipe, which communicates with the air-duct E preferably at the center of its length and through its side. To roo the pipe P is attached a suitable two-way valve V, with which communicate an airblast pipe S and an air-suction pipe S. The said valve is' preferably formed of a cylindrical shell arranged to rotate in acylindrical case R, which latter is connected axially at right angles to the pipe P and has its two ends open, and the pipes S S are connected, respectively, to said open ends. The valve V is formed with a diaphragm V, extending diagonally across the interior thereof, as shown in Fig 7 of the drawings, and atopposite sides of this diaphragm and at diametrically-opposite points in the cylindrical shell of the valve said shell is provided with an air-blast port I) and air-suction port Z), the latter of which is longer in the direction of the circumference oi. the shell than the former, for the purpose hereinafter explained.

The valve-case R is provided with a port a, by which it communicates with the pipe P, and diametrically opposite this portare waste-ports a through the valve-case. The shaft f of the valve V is journaled in suitable bearings g 9, formed 011 the pipes S S, and in a bearing on a pedestal I, secured to the top of one of the corners of the vat A, and a d.riv-.

ing-pulley G is attached to said shaft. The pipes S S are connected with a suitable air-' blowing and air-exhausting apparatus, which may be either LLLjLllhDllllLRQ) a fan-blower L, as shown in Fig. 2 of the drawings, or any other suitable and well-known machine or apparatus adapted to produce air-blasts and airsuctions, respectively, through the pipe S and pipe S.

The operation of my improved pulp-vat and its described appurtenances is as follows: The liquid-pulp, being admitted in the vat, flows across the top of the screen-plates. At the same time the air-blowing and air-exhaustin g apparatusL is setin motion, andalso the valve V. The rotation of the latter brings the blast-pipe S and suction-pipe S alternately in and out of communication with the pipe P,

and thereby produces a corresponding air-' blast and air-exhaust in the space between the screen and subjacent bottom of the vat. The air-blast port I) of the "alve, being shorter than the air-suction port Z) thereof, causes short and forcible puffs of air, which, being forced up through the interstices of the screen, clears the said interstices from any superincumbent'material an d long downward drafts of air through the interstices, and in this manner the screening process is materially expedited. In order to distribute the air more uniformly underneath the screen, I place in front of the mouth of the pipe P a bathe-plate h, as shown in Figs. 4 and 5 of the drawings. The screened pulp flows from the inclined bottom A of the vat to the pipe 0, as here inbefore described.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The combination, with the pulp-vat and screen in said-vat, of an air-space under the screen, an air-blast pipe and an air-suction pipe communicating with said air-space, and an air-blowing and air-exhausting apparatus connected to the aforesaid pipe, as set forth.

2. The combination, with the pulp-vat and screen in said vat, of an air-space under said screen, an air-pipe communicating with the said air-space, a two-way valve connected to said air-pipe, an air-blast pipe and an air-suction pipe connected to the case of said valve and respectively in communication with the two ways of the valve, and an air-blowin g and air-exhausting apparatus connected to the said blast and suction pipes, as set forth.

, 3. The combination, with the pulp-vat and screen in said vat, of an air-space under said screen, an air-duct extending along one side of the vat and having ports communicating with the aforesaid air-space, an air-blast pipe and an air-suction pipe communicating with the aforesaid air-duct, and an air-blowingand air-exhausting apparatus connected to the said blast-pipe and suction-pipe, substantially as set forth.

4. The combination, with the pulp-vat and screen, of an air-space under said screen, an air-duct extending along one side of the vat and having ports communicating with the said air-space, an air-pipe communicating with the aforesaid air-duct atthe center of its length, a baffie-plate in front of the air-pipe, a twoway valve connected to said air-pipe, an airblast pipe and an air-suction pipe connected to the case of said valve and respectively in communication with the two ways of the valve, and an air-blowin g and air-exhausting apparatus connected to the said blast and suction pipes, substantially as described and shown.

5. The combination of the pulp-vat formed with a bottom inclining from one side of the vat and with an air'duct along the elevated side of the bottom and a pulp-trough along the lower side of the same, the screen arranged over the inclined bottom with an air-space between them and communicating with the aforesaid air-duct, an air-blast pipe and an air-suction pipe communicating with the airduct in the vat, an d an air-blowing and air-exhaust apparatus connected to the said blast and exhaust pipes, as set forth.

6. The combination of the pulp-vat formed with 'a bottom inclining from one side of the vat and with an air-duct along the elevated side of the bottom and a pulp-trough along the lower side of the said bottom, the screen arranged over said bottom with an airspace between them and communicating with the aforesaid air-duct, an air-pipe communicatlng with the said air-duct at the center of its length, a baffle-plate in front'of the discharge.

C to the said blast and suction pipes, substantially as described and shown.

7. In combination with the pulp-vat and screen arranged with an air-space under said screen, the air-pipe P, communicating with said air-space, the valve-case R, of eylind rieal form, connected to the said pipe axially at right angles and having open ends and provided with the port a, communicating with the pipe P, the pipes S S, connected to the open ends of the valve-case, the valve V, consisting of a cylindrical shell arranged to retate in the aforesaid case and having the diaphragm V extended diagonally across the interior of the shell and ports I) Z) through the shell respectively at opposite sides of the diaphragm, and an air-blowing and air-exhausting apparatus connected to the pipes S S, substantially as described and shown.

8. I11 combination with the pulp-vat and screen arranged with an air-space under the screen, and the pipe P, communicating with said air-space, the valve-case R, of cylindrical form, connected to said pipe axially at right angles and having open ends, and provided with the port a, communicating with the pipe P and waste-port a, diametrically opposite the port a, the blast and suction pipes S S, connected, respectively, to the two open ends of the valve-case, the valve V, consisting of a cylindrical shell arranged to rotate in the aforesaid case and having the diaphragm V extended diagonally across the interior of the shell, and blast and suction ports Z) I) through the shell respectively at opposite sides of the diaphragm, said suction-port being longer in the direction of the circumference of the valve than the blast-port, and an air-blowing and air-exhausting apparatus connected to the pipes S S, substantially as described and'4oshown.

In testimony whereof I have hereunto signed my name this 0th day of April, 1889. 

